Lasers have been classified according to the potential for causing biological damage. The Laser Institute of America Standard ANSI Z136.1 is used to classify lasers. Government organizations also have standards for the use of lasers. See, for example, 29 C.F.R. 1926.102(b)(2) and 21 C.F.R. 1040. In general, Class I (eye safe) lasers do not emit radiation at known hazard levels. For higher class lasers, eye protection, training, safety protocols, and the like may be required. This is not generally true for Class I lasers.
Those skilled in the art have devised various safety measures for lasers. For example, U.S. Pat. No. 8,576,382, incorporated herein by this reference, discloses the use of a non-eye safe laser (in a LIBS system, for example). The operational range to the intended target is known and if a range unit determines the range to the target while the system is in use is greater than the operational range of the system, the non-eye safe laser is disabled. See also U.S. Pat. No. 7,676,061 incorporated herein by this reference.
In some applications, an eye safe laser for a handheld LIBS analyzer is desired. See U.S. patent application Ser. Nos. 13/746,110 (U.S. Patent Application Pub. No. 20140204378A1) and Ser. No. 14/179,670 (U.S. Patent Application Pub. No. 20140204377A1) by the assignee hereof and incorporated herein by this reference. One reason for incorporating an eye safe laser is to eliminate the regulatory requirements placed on higher class lasers. Still, a higher power (e.g., 6-10 mJ) laser may be needed to detect certain elements in certain samples or targets. A higher power laser may also provide lower detection limits.